MAPT and infection: None of the many hypothesized causes has gained unanimous acceptance: the two main current proposals are infection (or infection-related), and toxins—neither escaping significant critique.6 A third, based on the first significant neuropathological autopsy study in NS, proposed that the disorder was a novel tauopathy16 but later studies differed, failing to disclose any tau-positive neuronal neurofibrillary tangles or pre-tangles.17–19